Can I add a subwoofer? [Archive] - Audio & Video Forums

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markow202
05-09-2006, 09:48 AM
Hey Guys!

I have for my room a *rare* Pioneer 280w RMS mini-type system (not so mini) and im looking for even more bass than the 2- 8 inch woofers put out. I have a speaker selector currently hooked up to it which I use to connect an additional set of BOSE 161 small bookshelve speakers to add some more sound to the other end of my room since its big. Works great and ive had 3 parties with this system to its limits without it cutting out once.

I seen a POLK audio self powered subwoofer for sale and several others of the like. How do these exactly hook up or is it possible in my case with this system? Would it connect into the speaker selector and then into a power plug?

Again, looking to work around this system and add more bass.

Thanks

pitbosskev
05-09-2006, 10:03 AM
Hi there,

To be honest I wouldn't invest to much more money into a mini system. Good powered subs aren't cheap and could cost as much or more than your system. It might be possible to hook it up if you system has RCA outputs that you could run to the sub. Also the sub might have inputs for speaker wire. The problem with this is it can overload your system, especially since your are running 4 speakers off of it. Hope this helps a bit.

markow202
05-09-2006, 11:07 AM
Thanks. http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0665000FS10049583&catid=

This Polk Sub at a good price gave me the idea. It would cost much less than a whole new system IMO but I dont know how it would connect. Being self-powered would it still overload?

nightflier
05-09-2006, 02:04 PM
Mark,

That sub won't give you much bass. It is rated to go down to just 35Hz, which is perhaps 10Hz. lower than your speakers. Also at 100W / 50 W it won't do much for you in the power department either. Polk isn't really known for making decent subs. You might want to consider a second-hand sub with a little more boom, like these on eBay:

http://cgi.ebay.com/MONITOR-AUDIO-ASW110-SUBWOOFER_W0QQitemZ9721396173QQcategoryZ3275QQrdZ1 QQcmdZViewItem
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=9722228024&fromMakeTrack=true

And both of these have speaker level inputs & outputs so that you can connect them between your mini-system and the speakers even if you don't have a dedicated sub-out. Even this one would be a better deal (although it doesn't have the speaker-level outs):

http://cgi.ebay.com/Axiom-125-Subwoofer_W0QQitemZ9722678850QQcategoryZ3275QQrdZ1 QQcmdZViewItem

markow202
05-09-2006, 02:36 PM
Thanks!! I might place a bid on those 2...but they will work connected with speaker wire?

How exactly would I connect a sub now...im guessing through the speaker selector like the rest of the speakers.

Woochifer
05-09-2006, 06:28 PM
Thanks!! I might place a bid on those 2...but they will work connected with speaker wire?

How exactly would I connect a sub now...im guessing through the speaker selector like the rest of the speakers.

It will work because that sub has speaker level inputs. But, you'll need to tinker with the crossover setting and be careful with where you place the unit because it does not have a high pass filter that filters out the low frequencies before redirecting the output to the speakers.

markow202
05-09-2006, 07:44 PM
So im guessing the sub will then try to play the full range of sound?

Woochifer
05-10-2006, 12:30 PM
So im guessing the sub will then try to play the full range of sound?

No, the low pass filter will determine the upper range that your subwoofer will play, so you can set the upper limit for the sub. The only time you would bypass the low pass filter on the sub would be if you have a home theater receiver performing the bass management functions.

The high pass filter (which does not come with most low end subwoofers) would filter out the low frequencies that get redirected to the speakers and/or amplifier. This type of arrangement is better for integrating your main speakers with the subwoofer. Most subs nowadays assume that a home theater receiver will do the high pass filtering, so they don't include the feature.

markow202
05-11-2006, 05:16 AM
Sounds good thanks alot.

nightflier
05-11-2006, 09:53 AM
Mark,

I know it's a bit out of your price range, but subs from Hsu, SVS, and the mid-range of Velodyne on up will have much better performance. These companies make subs as their bread-n-butter product line and they know a thing or two about making a decent sub. Hsu & SVS, in particular will provide you with excellent pre-sales support and recommendations because they are smaller companies. You might want to shoot them an email.

markow202
05-11-2006, 12:26 PM
Ya thanks i'll mostlikely contact them.

Very helpful forum here BTW, and I thought for a second I was gonna get "told" for having a mini-system...but its a good one and not so mini and from Pioneer. The Bose is for added ambience in the room.

Woochifer
05-12-2006, 07:35 AM
Mark,

I know it's a bit out of your price range, but subs from Hsu, SVS, and the mid-range of Velodyne on up will have much better performance. These companies make subs as their bread-n-butter product line and they know a thing or two about making a decent sub. Hsu & SVS, in particular will provide you with excellent pre-sales support and recommendations because they are smaller companies. You might want to shoot them an email.

One potential drawback with Hsu and SVS in this case is that their lower end models do not include speaker level inputs/outputs. Unless the mini-system that Markow202 uses includes a line-level subwoofer output, there's no way to connect a sub that lacks speaker-level inputs without adding an external bass management device like the Paradigm X-20. If he contacts Hsu or SVS, it would be helpful to hear from them what options they can offer for his setup.

Resident Loser
05-12-2006, 09:42 AM
...but I find a 280W mini-system hard to believe...given the numbers game manufacturers like to play using IPP, dynamic power, music power, DIN and EIAJ with single channel-driven, odd impedance ratings and poor distortion specs you may be dealing with 20-25 FTC RMS watts...

The Polk 50 watt sub is probably just what you need to give the amplifier section of your system some breathing room and extend your frequency response to a legit 40Hz@-3dB...

I've been considering one for my Onkyo MC35TECH mini-system which on a good day, with the wind to it's back, produces 15WpcRMS@8 Ohms (the included speakers are 5 or 6 Ohms which bumps it to around 17 or 18 Wpc), both channels driven @1kHZ with 0.6%THD...bump that number up using IPP (Instantaneous Peak Power) wishful thinking, into 4 Ohms and it's around a system total of 240Watts or 120 IPP Wpc...even using the more conservative but non-FTC EIAJ spec into 4 Ohms it jumps to 29Wpc...

jimHJJ(...Do you know your model number?...)

markow202
05-12-2006, 12:49 PM
Most mini-systems I seen say for example just "100 watts" but this one has posted 280 watts RMS on the unit. It is a fairly big cabinet for the amp aswell and I never was able to get the amp to clip. Its driving 2 big 8"inch woofers with rubber surrounds and 2 tweeters...this is per speaker. It has optional rear speaker output aswell and I did have the small BOSE 161s at first, hooked into the rear output but then I decided to add a speaker selector and put the BOSE as full range. With proper tweaking (which meant less bass now because of the additional smaller speakers) I get no distortion but you can tell, some power was taken as the overall volume goes down sligthly when the BOSE are selected "on".

Still never had it cut out eitheir or heat up...had it one notch below its flashing "MAX" volume level (which is 23, so i had it on 22) for about 3 hrs straight for a party. Never a complaint so im guessing this is a true 280 watts?

Cant see anything below 50 watts able to do this.

Woochifer
05-12-2006, 02:46 PM
Most mini-systems I seen say for example just "100 watts" but this one has posted 280 watts RMS on the unit. It is a fairly big cabinet for the amp aswell and I never was able to get the amp to clip. Its driving 2 big 8"inch woofers with rubber surrounds and 2 tweeters...this is per speaker. It has optional rear speaker output aswell and I did have the small BOSE 161s at first, hooked into the rear output but then I decided to add a speaker selector and put the BOSE as full range. With proper tweaking (which meant less bass now because of the additional smaller speakers) I get no distortion but you can tell, some power was taken as the overall volume goes down sligthly when the BOSE are selected "on".

Still never had it cut out eitheir or heat up...had it one notch below its flashing "MAX" volume level (which is 23, so i had it on 22) for about 3 hrs straight for a party. Never a complaint so im guessing this is a true 280 watts?

Cant see anything below 50 watts able to do this.

Loudness does not mean anything with regard to the accuracy of an output spec. There are many many ways of doctoring the wattage specs to say whatever a manufacturer wants it to say. Quoting the spec as a summed total is generally the most nonsensical method, especially with a multichannel mini-system, because even if your system quotes an output of 280 watts RMS, it does not mean that the system is capable of outputing that wattage to all channels simultaneously. The wattage spec means nothing unless it's expressed in terms of the output PER CHANNEL.

You've already mentioned that your system has rear speaker outputs. Presumably this means that the output is going to at least four speakers. On a per channel basis, this means that the output is 70 watts. And it gets worse, just because a system can output 70 watts per channel does not mean that it can drive 70 watts per channel with ALL channels driven simultaneously. Therefore, that 280 watt spec does not mean anything because the system will never actually output that amount. It's a con game that most manfacturers engage in with their spec sheets. You need to read the fine print.

Keep in mind that most speakers have a sensitivity somewhere around 85-90 db with many speakers that operate at even higher efficiency levels (horn speakers can have efficiency ratings above 110 db). This means that it takes just ONE WATT to drive those speakers to 85-90 db, which is plenty loud. With those same speakers, driving them to 95-100 db, which is VERY loud, will only require TEN watts. Bottomline is that there's a lot more to ponder than just the wattage rating when evaluating a system. 50 watts per channel will probably bring the cops to your door answering your neighbors' noise complaints.

markow202
05-13-2006, 11:21 PM
Any signs I could tell, if my system is being overloaded too much? Would it be only if it heats up and stops playing which it never did?